Semester 2: Unit 4: Session 6 - Human Heredity

What is human heredity?

The study of how genes are passed from parents to offspring and how they contribute to human traits.

What inheritance pattern do many human genes follow?

The Mendelian dominant/recessive pattern.

What is a pedigree?

A detailed family tree that tracks traits and helps researchers study inheritance patterns.

What is the human genome?

All the DNA in a typical human cell and the complete set of chromosomes.

How many autosomes do humans have?

22 pairs of autosomes.

What is an autosome?

Any chromosome that is not a sex chromosome.

What is an example of a human gene that follows a dominant/recessive pattern?

MC1R, which affects skin and hair color.

What are codominant genes?

Genes in which both alleles are expressed in the phenotype.

What is a sex-linked gene?

A gene located on a sex chromosome, usually the X chromosome.

What is a mutation?

A change in the DNA sequence.

What causes sickle cell anemia?

A single mutation in the hemoglobin gene.

How do red blood cells change in sickle cell anemia?

They change from normal disk shapes to sickle shapes.

Why are sickle-shaped red blood cells dangerous?

They do not move through capillaries efficiently.

What causes the sickle shape in sickle cell anemia?

mutated hemoglobin forms fibers inside red blood cells.

What is cystic fibrosis?

A genetic disorder caused by a mutation in a membrane protein that clears mucus from the lungs.

What are the effects of cystic fibrosis?

Chronic lung infections and damage to lung tissue.

What is nondisjunction?

The failure of chromosomes to separate properly during meiosis.

What can result from nondisjunction?

Gametes with the wrong number of chromosomes.

What causes Down syndrome?

An extra chromosome (trisomy 21).

What is gene therapy?

A treatment that provides corrected genes to individuals with mutations.